store: unindent most of the contents of the for loop in _auxencode()

by refactoring

    for i, n in enumerate(res):
        if n:
            <main code block>

to

    for i, n in enumerate(res):
        if not n:
            continue
        <main code block>

(no functional change)

mercurial/store.py

@@ -143,7 +143,8 b' def _auxencode(path, dotencode):'
     '''
     res = path.split('/')
     for i, n in enumerate(res):
-        if n:
+        if not n:
+            continue
             if dotencode and n[0] in '. ':
                 n = "~%02x" % ord(n[0]) + n[1:]
                 res[i] = n